This invention relates to a novel, crystalline, ethercarboxylate monohydrate particularly suited for processing into detergent formulations and to processes for preparation of such monohydrate. It has been discovered that a compound represented by the formula: ##STR1## EXHIBITS EXCELLENT FUNCTIONALITY AS A DETERGENCY BUILDER. This compound and its use as a detergency builder is described in U.S. Pat. No. 3,865,755, the disclosure of said patent being incorporated herein by reference. Under conditions of high relative humidity, the amorphous form of this compound tends to be hygroscopic and water uptake can result in problems of agglomeration of the compound per se or the detergent formulations in which it is employed. A higher hydrate (tri or tetra) of the compound, which is substantially non-hygroscopic, can be prepared by evaporating a solution of the compound at ambient temperatures. However, the trihydrate loses water of hydration at relatively low temperatures (around 100.degree. C.) and if rapidly dried, as in spray-drying processes for the preparation of detergent formulations, is converted to amorphous form.
It is apparent, therefore, that provision of a form of the above-discussed compound which is relatively non-hygroscopic and thermally stable would constitute an advance in the art.